(1) Field of the Invention
The present invention relates to a method for separating a protective tape, and an apparatus using the same. In this method, a separating adhesive tape is joined to a surface of a protective tape joined to a front face of a semiconductor wafer in such a manner that a joining member presses the separating adhesive tape against the protective tape, and then the protective tape is separated together with the separating adhesive tape from the front face of the semiconductor wafer.
(2) Description of the Related Art
In order to make a semiconductor wafer (hereinafter, simply referred to as a “wafer”) thin, there is adopted a mechanical method such as grinding or polishing or a chemical method such as etching. When a wafer is subjected to processing by such method, a protective tape is joined to a front face thereof in order to protect a wiring pattern formed on the front face. The wafer is subjected to polishing with the protective tape joined thereto, and then is held by a ring-shaped frame in such a manner that a supporting viscous tape is joined to a back face thereof. Thereafter, the protective tape is separated and removed from the front face of the wafer held by the ring-shaped frame.
For example, JP-A 05-063077 (1993) discloses a method for separation and removal of a protective tape. Herein, a separating adhesive tape is joined to a surface of a protective tape joined to a front face of a wafer by means of a joining member such as a roller or an edge member, and then is separated and removed together with the protective tape from the front face of the wafer while being reeled.
However, the aforementioned conventional method has the following problems.
That is, if the protective tape joined to the wafer has a high adhesion property, it is difficult to form a folded portion, serving as a starting point of separation of the protective tape, at a peripheral edge of the wafer even when the separating adhesive tape is joined to the protective tape. Consequently, the protective tape cannot be separated from the wafer.
In addition, the protective tape cut in a protective tape cutting step has a trapezoidal sectional shape (that is, an adhesive face of the protective tape becomes longer in width than a surface thereof). Consequently, adhesion between the separating adhesive tape and the peripheral edge of the wafer is hardly achieved, so that a separating stress is hardly applied to the separating adhesive tape upon separation of the separating adhesive tape, resulting in poor separation accuracy.